1. Field of the Invention
The present invention relates to an optical fiber, an optical fiber tape, an optical cable, and an optical connector equipped with an optical fiber, which are suitable for an optical transmission line through which signal light propagates, an optical transmission line of optical access type in particular, in an optical communication system.
2. Related Background Art
Optical communication systems enable high-speed transmission of a large volume of information by transmitting signal light through optical transmission lines. As an optical transmission line through which the signal light propagates, an optical fiber is employed, for example. Since the chromatic dispersion of silica glass, which is a material for an optical fiber, becomes zero in the vicinity of a wavelength of 1.3 μm, single-mode optical fibers for the band of 1.3 μm having a zero-dispersion wavelength near the wavelength of 1.3 μm have been utilized in conventional optical communication systems. Also proposed is a single-mode optical fiber for the band of 1.55 μm, suitable for optical communications in the band of 1.55 μm, having a zero-dispersion wavelength near the wavelength of 1.3 μm. Further, taking account of the fact that the transmission loss of silica glass is minimized at a wavelength of 1.55 μm, a dispersion-shifted optical fiber whose refractive index profile is designed so as to attain a zero-dispersion wavelength near the wavelength of 1.55 μm has been utilized as the above-mentioned optical transmission line. Structures and characteristics of such optical fibers are described, for example, in literature 1—Shojiro Kawakami, et al., “Optical fiber and Fiber type Devices”, Baifu-kan, Jul. 10, 1996, pp. 90–113.
Also, optical fibers having a zero-dispersion wavelength between wavelengths of 1.3 μm and 1.55 μm have been proposed as disclosed in Japanese Patent Application Laid-Open No. HEI 11-281840 and literature 2—K. Nakajima, et al., “Design consideration for 1.38 μm zero-dispersion fiber for access and metropolitan networks”, The 2001 IEICE Communications Society Conference, SB-12-1 (2001).